. Genetics is a branch of concerned with the study of, and in living. The discoverer of genetics is, a late 19th-century scientist.

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Mendel studied 'trait inheritance', patterns in the way traits are handed down from parents to offspring. He observed that organisms (pea plants) inherit traits by way of discrete 'units of inheritance'. This term, still used today, is a somewhat ambiguous definition of what is referred to as a.

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Inheritance and inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded beyond inheritance to studying the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the, the organism (e.g. ), and within the context of a population. Genetics has given rise to a number of subfields, including.

Organisms studied within the broad field span the domains of life (, and ). Genetic processes work in combination with an organism's environment and experiences to influence development and, often referred to as. The or environment of a cell or organism may switch gene transcription on or off. A classic example is two seeds of genetically identical corn, one placed in a temperate climate and one in an arid climate. While the average height of the two corn stalks may be genetically determined to be equal, the one in the only grows to half the height of the one in the temperate climate due to lack of water and nutrients in its environment. Leads to the averaging out of every characteristic, which as the engineer pointed out, makes evolution by natural selection impossible. Other theories of inheritance preceded Mendel's work.

A popular theory during the 19th century, and implied by 's 1859, was: the idea that individuals inherit a smooth blend of traits from their parents. Mendel's work provided examples where traits were definitely not blended after hybridization, showing that traits are produced by combinations of distinct genes rather than a continuous blend. Blending of traits in the progeny is now explained by the action of multiple genes with.

Another theory that had some support at that time was the: the belief that individuals inherit traits strengthened by their parents. This theory (commonly associated with ) is now known to be wrong—the experiences of individuals do not affect the genes they pass to their children, although evidence in the field of has revived some aspects of Lamarck's theory. Other theories included the of (which had both acquired and inherited aspects) and 's reformulation of pangenesis as both particulate and inherited. Mendelian and classical genetics. The molecular basis for. Each strand of DNA is a chain of, matching each other in the center to form what look like rungs on a twisted ladder. Although genes were known to exist on chromosomes, chromosomes are composed of both protein and DNA, and scientists did not know which of the two is responsible for inheritance.

In 1928, discovered the phenomenon of (see ): dead bacteria could transfer to 'transform' other still-living bacteria. Sixteen years later, in 1944, the identified DNA as the molecule responsible for transformation.

The role of the nucleus as the repository of genetic information in eukaryotes had been established by in 1943 in his work on the single celled alga. The in 1952 confirmed that DNA (rather than protein) is the genetic material of the viruses that infect bacteria, providing further evidence that DNA is the molecule responsible for inheritance. And determined the structure of DNA in 1953, using the work of and that indicated DNA has a structure (i.e., shaped like a corkscrew). Their double-helix model had two strands of DNA with the nucleotides pointing inward, each matching a complementary nucleotide on the other strand to form what look like rungs on a twisted ladder.

This structure showed that genetic information exists in the sequence of nucleotides on each strand of DNA. The structure also suggested a simple method for: if the strands are separated, new partner strands can be reconstructed for each based on the sequence of the old strand. This property is what gives DNA its semi-conservative nature where one strand of new DNA is from an original parent strand. Although the structure of DNA showed how inheritance works, it was still not known how DNA influences the behavior of cells. In the following years, scientists tried to understand how DNA controls the process of. It was discovered that the cell uses DNA as a template to create matching, molecules with very similar to DNA. The nucleotide sequence of a messenger RNA is used to create an sequence in protein; this translation between nucleotide sequences and amino acid sequences is known as the.

With the newfound molecular understanding of inheritance came an explosion of research. A notable theory arose from in 1973 with her amendment to the through publishing the. In this theory, Ohta stressed the importance of natural selection and the environment to the rate at which genetic evolution occurs. One important development was chain-termination in 1977. This technology allows scientists to read the nucleotide sequence of a DNA molecule. In 1983, developed the, providing a quick way to isolate and amplify a specific section of DNA from a mixture.

The efforts of the, Department of Energy, NIH, and parallel private efforts by led to the sequencing of the in 2003. Features of inheritance Discrete inheritance and Mendel's laws.

A depicting a cross between two pea plants heterozygous for purple (B) and white (b) blossoms. At its most fundamental level, inheritance in organisms occurs by passing discrete heritable units, called, from parents to offspring.

This property was first observed by, who studied the segregation of heritable traits in plants. In his experiments studying the trait for flower color, Mendel observed that the flowers of each pea plant were either purple or white—but never an intermediate between the two colors. These different, discrete versions of the same gene are called. In the case of the pea, which is a species, each individual plant has two copies of each gene, one copy inherited from each parent. Many species, including humans, have this pattern of inheritance.

Diploid organisms with two copies of the same allele of a given gene are called at that, while organisms with two different alleles of a given gene are called. The set of alleles for a given organism is called its, while the observable traits of the organism are called its. When organisms are heterozygous at a gene, often one allele is called as its qualities dominate the phenotype of the organism, while the other allele is called as its qualities recede and are not observed.

Some alleles do not have complete dominance and instead have by expressing an intermediate phenotype, or by expressing both alleles at once. When a pair of organisms, their offspring randomly inherit one of the two alleles from each parent.

These observations of discrete inheritance and the segregation of alleles are collectively known as or the Law of Segregation. Notation and diagrams. Genetic pedigree charts help track the inheritance patterns of traits.

Geneticists use diagrams and symbols to describe inheritance. A gene is represented by one or a few letters. Often a '+' symbol is used to mark the usual, for a gene. In fertilization and breeding experiments (and especially when discussing Mendel's laws) the parents are referred to as the 'P' generation and the offspring as the 'F1' (first filial) generation. When the F1 offspring mate with each other, the offspring are called the 'F2' (second filial) generation. One of the common diagrams used to predict the result of cross-breeding is the. When studying human genetic diseases, geneticists often use to represent the inheritance of traits.

These charts map the inheritance of a trait in a family tree. Multiple gene interactions. Human height is a trait with complex genetic causes.

's data from 1889 shows the relationship between offspring height as a function of mean parent height. Organisms have thousands of genes, and in sexually reproducing organisms these genes generally assort independently of each other. This means that the inheritance of an allele for yellow or green pea color is unrelated to the inheritance of alleles for white or purple flowers. This phenomenon, known as ' or the 'law of independent assortment,' means that the alleles of different genes get shuffled between parents to form offspring with many different combinations. (Some genes do not assort independently, demonstrating, a topic discussed later in this article.) Often different genes can interact in a way that influences the same trait. In the ( Omphalodes verna), for example, there exists a gene with alleles that determine the color of flowers: blue or magenta. Another gene, however, controls whether the flowers have color at all or are white.

When a plant has two copies of this white allele, its flowers are white—regardless of whether the first gene has blue or magenta alleles. This interaction between genes is called, with the second gene epistatic to the first. Many traits are not discrete features (e.g. Purple or white flowers) but are instead continuous features (e.g. Human height and ).

These are products of many genes. The influence of these genes is mediated, to varying degrees, by the environment an organism has experienced. The degree to which an organism's genes contribute to a complex trait is called. Measurement of the heritability of a trait is relative—in a more variable environment, the environment has a bigger influence on the total variation of the trait. For example, human height is a trait with complex causes. It has a heritability of 89% in the United States. In Nigeria, however, where people experience a more variable access to good nutrition and, height has a heritability of only 62%.

Molecular basis for inheritance DNA and chromosomes. Bases pair through the arrangement of between the strands. The basis for genes is (DNA).

DNA is composed of a chain of, of which there are four types: (A), (C), (G), and (T). Genetic information exists in the sequence of these nucleotides, and genes exist as stretches of sequence along the DNA chain. Are the only exception to this rule—sometimes viruses use the very similar molecule instead of DNA as their genetic material. Viruses cannot reproduce without a and are unaffected by many genetic processes, so tend not to be considered living organisms. DNA normally exists as a double-stranded molecule, coiled into the shape of a.

Each nucleotide in DNA preferentially pairs with its partner nucleotide on the opposite strand: A pairs with T, and C pairs with G. Thus, in its two-stranded form, each strand effectively contains all necessary information, redundant with its partner strand. This structure of DNA is the physical basis for inheritance: duplicates the genetic information by splitting the strands and using each strand as a template for synthesis of a new partner strand.

Genes are arranged linearly along long chains of DNA base-pair sequences. In, each cell usually contains a single circular, while organisms (such as plants and animals) have their DNA arranged in multiple linear chromosomes.

These DNA strands are often extremely long; the largest human chromosome, for example, is about 247 million in length. The DNA of a chromosome is associated with structural proteins that organize, compact, and control access to the DNA, forming a material called; in eukaryotes, chromatin is usually composed of, segments of DNA wound around cores of proteins. The full set of hereditary material in an organism (usually the combined DNA sequences of all chromosomes) is called the. While organisms have only one copy of each chromosome, most animals and many plants are, containing two of each chromosome and thus two copies of every gene.

The two alleles for a gene are located on identical of the two, each allele inherited from a different parent. 's 1882 diagram of eukaryotic cell division. Chromosomes are copied, condensed, and organized. Then, as the cell divides, chromosome copies separate into the daughter cells. Many species have so-called that determine the gender of each organism.

In humans and many other animals, the contains the gene that triggers the development of the specifically male characteristics. In evolution, this chromosome has lost most of its content and also most of its genes, while the is similar to the other chromosomes and contains many genes. The X and Y chromosomes form a strongly heterogeneous pair. Reproduction. Main articles: and When cells divide, their full genome is copied and each inherits one copy.

This process, called, is the simplest form of reproduction and is the basis for. Asexual reproduction can also occur in multicellular organisms, producing offspring that inherit their genome from a single parent. Offspring that are genetically identical to their parents are called. Organisms often use to generate offspring that contain a mixture of genetic material inherited from two different parents.

The process of sexual reproduction alternates between forms that contain single copies of the genome and double copies. Haploid cells fuse and combine genetic material to create a diploid cell with paired chromosomes. Diploid organisms form haploids by dividing, without replicating their DNA, to create daughter cells that randomly inherit one of each pair of chromosomes. Most animals and many plants are diploid for most of their lifespan, with the haploid form reduced to single cell such as. Although they do not use the haploid/diploid method of sexual reproduction, have many methods of acquiring new genetic information.

Some bacteria can undergo, transferring a small circular piece of DNA to another bacterium. Bacteria can also take up raw DNA fragments found in the environment and integrate them into their genomes, a phenomenon known as. These processes result in, transmitting fragments of genetic information between organisms that would be otherwise unrelated. Recombination and genetic linkage. 's 1916 illustration of a double crossover between chromosomes. The diploid nature of chromosomes allows for genes on different chromosomes to or be separated from their homologous pair during sexual reproduction wherein haploid gametes are formed. In this way new combinations of genes can occur in the offspring of a mating pair.

Genes on the same chromosome would theoretically never recombine. However, they do, via the cellular process of. During crossover, chromosomes exchange stretches of DNA, effectively shuffling the gene alleles between the chromosomes. This process of chromosomal crossover generally occurs during, a series of cell divisions that creates haploid cells. The first cytological demonstration of crossing over was performed by Harriet Creighton and Barbara McClintock in 1931.

Their research and experiments on corn provided cytological evidence for the genetic theory that linked genes on paired chromosomes do in fact exchange places from one homolog to the other. The probability of chromosomal crossover occurring between two given points on the chromosome is related to the distance between the points. For an arbitrarily long distance, the probability of crossover is high enough that the inheritance of the genes is effectively uncorrelated. For genes that are closer together, however, the lower probability of crossover means that the genes demonstrate; alleles for the two genes tend to be inherited together.

The amounts of linkage between a series of genes can be combined to form a linear that roughly describes the arrangement of the genes along the chromosome. Gene expression Genetic code. The: Using a, DNA, through a intermediary, specifies a protein. Genes generally their functional effect through the production of, which are complex molecules responsible for most functions in the cell. Proteins are made up of one or more polypeptide chains, each of which is composed of a sequence of, and the DNA sequence of a gene (through an RNA intermediate) is used to produce a specific.

This process begins with the production of an molecule with a sequence matching the gene's DNA sequence, a process called. This molecule is then used to produce a corresponding amino acid sequence through a process called. Each group of three nucleotides in the sequence, called a, corresponds either to one of the twenty possible amino acids in a protein or an; this correspondence is called the.

The flow of information is unidirectional: information is transferred from nucleotide sequences into the amino acid sequence of proteins, but it never transfers from protein back into the sequence of DNA—a phenomenon called the. The specific sequence of amino acids in a unique three-dimensional structure for that protein, and the three-dimensional structures of proteins are related to their functions. Some are simple structural molecules, like the fibers formed by the protein.

Proteins can bind to other proteins and simple molecules, sometimes acting as by facilitating within the bound molecules (without changing the structure of the protein itself). Protein structure is dynamic; the protein bends into slightly different forms as it facilitates the capture, transport, and release of oxygen molecules within mammalian blood. A within DNA can cause a change in the amino acid sequence of a protein. Because protein structures are the result of their amino acid sequences, some changes can dramatically change the properties of a protein by destabilizing the structure or changing the surface of the protein in a way that changes its interaction with other proteins and molecules. For example, is a human that results from a single base difference within the for the β-globin section of hemoglobin, causing a single amino acid change that changes hemoglobin's physical properties. Sickle-cell versions of hemoglobin stick to themselves, stacking to form fibers that distort the shape of carrying the protein. These sickle-shaped cells no longer flow smoothly through, having a tendency to clog or degrade, causing the medical problems associated with this disease.

Some DNA sequences are transcribed into RNA but are not translated into protein products—such RNA molecules are called. In some cases, these products fold into structures which are involved in critical cell functions (e.g. RNA can also have regulatory effects through hybridization interactions with other RNA molecules (e.g. Nature and nurture. Have a temperature-sensitive pigment-production mutation. Although genes contain all the information an organism uses to function, the environment plays an important role in determining the ultimate phenotypes an organism displays.

The phrase ' refers to this complementary relationship. The phenotype of an organism depends on the interaction of genes and the environment. An interesting example is the coat coloration of the. In this case, the body temperature of the cat plays the role of the environment. The cat's genes code for dark hair, thus the hair-producing cells in the cat make cellular proteins resulting in dark hair.

But these dark hair-producing proteins are sensitive to temperature (i.e. Have a mutation causing temperature-sensitivity) and in higher-temperature environments, failing to produce dark-hair pigment in areas where the cat has a higher body temperature. In a low-temperature environment, however, the protein's structure is stable and produces dark-hair pigment normally. The protein remains functional in areas of skin that are colder—such as its legs, ears, tail and face—so the cat has dark-hair at its extremities.

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Environment plays a major role in effects of the human genetic disease. The mutation that causes phenylketonuria disrupts the ability of the body to break down the amino acid, causing a toxic build-up of an intermediate molecule that, in turn, causes severe symptoms of progressive intellectual disability and seizures. However, if someone with the phenylketonuria mutation follows a strict diet that avoids this amino acid, they remain normal and healthy. A common method for determining how genes and environment ('nature and nurture') contribute to a phenotype involves, or other siblings of.

Because identical siblings come from the same zygote, they are genetically the same. Fraternal twins are as genetically different from one another as normal siblings. By comparing how often a certain disorder occurs in a pair of identical twins to how often it occurs in a pair of fraternal twins, scientists can determine whether that disorder is caused by genetic or postnatal environmental factors – whether it has 'nature' or 'nurture' causes.

One famous example involved the study of the, who were all diagnosed with. However such tests cannot separate genetic factors from environmental factors affecting fetal development. Gene regulation. Main article: The genome of a given organism contains thousands of genes, but not all these genes need to be active at any given moment.

A gene is when it is being transcribed into mRNA and there exist many cellular methods of controlling the expression of genes such that proteins are produced only when needed by the cell. Are regulatory proteins that bind to DNA, either promoting or inhibiting the transcription of a gene. Within the genome of bacteria, for example, there exists a series of genes necessary for the synthesis of the amino acid. However, when tryptophan is already available to the cell, these genes for tryptophan synthesis are no longer needed. The presence of tryptophan directly affects the activity of the genes—tryptophan molecules bind to the (a transcription factor), changing the repressor's structure such that the repressor binds to the genes. The tryptophan repressor blocks the transcription and expression of the genes, thereby creating regulation of the tryptophan synthesis process. Transcription factors bind to DNA, influencing the transcription of associated genes.

Differences in gene expression are especially clear within, where cells all contain the same genome but have very different structures and behaviors due to the expression of different sets of genes. All the cells in a multicellular organism derive from a single cell, differentiating into variant cell types in response to external and and gradually establishing different patterns of gene expression to create different behaviors. As no single gene is responsible for the of structures within multicellular organisms, these patterns arise from the complex interactions between many cells. Within, there exist structural features of that influence the transcription of genes, often in the form of modifications to DNA and chromatin that are stably inherited by daughter cells. These features are called ' because they exist 'on top' of the DNA sequence and retain inheritance from one cell generation to the next.

Because of epigenetic features, different cell types within the same medium can retain very different properties. Although epigenetic features are generally dynamic over the course of development, some, like the phenomenon of, have multigenerational inheritance and exist as rare exceptions to the general rule of DNA as the basis for inheritance. Gene duplication allows diversification by providing redundancy: one gene can mutate and lose its original function without harming the organism. During the process of, errors occasionally occur in the polymerization of the second strand. These errors, called, can affect the phenotype of an organism, especially if they occur within the protein coding sequence of a gene. Error rates are usually very low—1 error in every 10–100 million bases—due to the 'proofreading' ability of. Processes that increase the rate of changes in DNA are called: mutagenic chemicals promote errors in DNA replication, often by interfering with the structure of base-pairing, while induces mutations by causing damage to the DNA structure.

Chemical damage to DNA occurs naturally as well and cells use mechanisms to repair mismatches and breaks. The repair does not, however, always restore the original sequence. In organisms that use to exchange DNA and recombine genes, errors in alignment during can also cause mutations. Errors in crossover are especially likely when similar sequences cause partner chromosomes to adopt a mistaken alignment; this makes some regions in genomes more prone to mutating in this way. These errors create large structural changes in DNA sequence –, of entire regions – or the accidental exchange of whole parts of sequences between different chromosomes. This is a diagram showing mutations in an RNA sequence. Figure (1) is a normal RNA sequence, consisting of 4 codons.

Figure (2) shows a missense, single point, non silent mutation. Figures (3 and 4) both show, which is why they are grouped together. Figure 3 shows a deletion of the second base pair in the second codon. Figure 4 shows an insertion in the third base pair of the second codon. Figure (5) shows a repeat expansion, where an entire codon is duplicated. Natural selection and evolution. Further information: Mutations alter an organism's genotype and occasionally this causes different phenotypes to appear.

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Most mutations have little effect on an organism's phenotype, health, or reproductive. Mutations that do have an effect are usually detrimental, but occasionally some can be beneficial. Studies in the fly suggest that if a mutation changes a protein produced by a gene, about 70 percent of these mutations will be harmful with the remainder being either neutral or weakly beneficial. An of organisms, constructed by the comparison of several sequences. Studies the distribution of genetic differences within populations and how these distributions change over time. Changes in the in a population are mainly influenced by, where a given allele provides a selective or reproductive advantage to the organism, as well as other factors such as,.

Over many generations, the genomes of organisms can change significantly, resulting in. In the process called, selection for beneficial mutations can cause a species to evolve into forms better able to survive in their environment. New species are formed through the process of, often caused by geographical separations that prevent populations from exchanging genes with each other. By comparing the between different species' genomes, it is possible to calculate the evolutionary distance between them. Genetic comparisons are generally considered a more accurate method of characterizing the relatedness between species than the comparison of phenotypic characteristics. The evolutionary distances between species can be used to form; these trees represent the and divergence of species over time, although they do not show the transfer of genetic material between unrelated species (known as and most common in bacteria).

Model organisms. The ( Drosophila melanogaster) is a popular in genetics research. Although geneticists originally studied inheritance in a wide range of organisms, researchers began to specialize in studying the genetics of a particular subset of organisms.

The fact that significant research already existed for a given organism would encourage new researchers to choose it for further study, and so eventually a few became the basis for most genetics research. Common research topics in model organism genetics include the study of and the involvement of genes in. Organisms were chosen, in part, for convenience—short generation times and easy made some organisms popular genetics research tools. Widely used model organisms include the gut bacterium, the plant, baker's yeast ( ), the nematode, the common fruit fly ( ), and the common house mouse ( ). Medicine.

Schematic relationship between, genetics. Seeks to understand how genetic variation relates to human health and disease. When searching for an unknown gene that may be involved in a disease, researchers commonly use and genetic to find the location on the genome associated with the disease.

At the population level, researchers take advantage of to look for locations in the genome that are associated with diseases, a method especially useful for not clearly defined by a single gene. Once a candidate gene is found, further research is often done on the corresponding (or ) genes of model organisms. In addition to studying genetic diseases, the increased availability of genotyping methods has led to the field of: the study of how genotype can affect drug responses. Individuals differ in their inherited tendency to develop, and cancer is a genetic disease. The process of cancer development in the body is a combination of events.

Occasionally occur within cells in the body as they divide. Although these mutations will not be inherited by any offspring, they can affect the behavior of cells, sometimes causing them to grow and divide more frequently. There are biological mechanisms that attempt to stop this process; signals are given to inappropriately dividing cells that should trigger, but sometimes additional mutations occur that cause cells to ignore these messages.

An internal process of occurs within the body and eventually mutations accumulate within cells to promote their own growth, creating a cancerous that grows and invades various tissues of the body. Normally, a cell divides only in response to signals called and and in response to growth-inhibitory signals.

It usually then divides a limited number of times and dies, staying within the where it is unable to migrate to other organs. To become a cancer cell, a cell has to accumulate mutations in a number of genes (three to seven) that allow it to bypass this regulation: it no longer needs growth factors to divide, continues growing when making contact to neighbor cells, ignores inhibitory signals, keeps growing indefinitely and is immortal, escapes from the epithelium and ultimately may be able to escape from the, cross the endothelium of a blood vessel, be transported by the bloodstream and colonize a new organ, forming deadly. Although there are some genetic predispositions in a small fraction of cancers, the major fraction is due to a set of new genetic mutations that originally appear and accumulate in one or a small number of cells that will divide to form the tumor and are not transmitted to the progeny. The most frequent mutations are a loss of function of, a, or in the p53 pathway, and gain of function mutations in the, or in other. Research methods.

A similar methodology is often used in. DNA can be manipulated in the laboratory. Are commonly used that cut DNA at specific sequences, producing predictable fragments of DNA.

DNA fragments can be visualized through use of, which separates fragments according to their length. The use of allows DNA fragments to be connected. By binding ('ligating') fragments of DNA together from different sources, researchers can create, the DNA often associated with. Recombinant DNA is commonly used in the context of: short circular DNA molecules with a few genes on them. In the process known as, researchers can amplify the DNA fragments by inserting plasmids into bacteria and then culturing them on plates of agar (to isolate – 'cloning' can also refer to the various means of creating cloned ('clonal') organisms). DNA can also be amplified using a procedure called the (PCR). By using specific short sequences of DNA, PCR can isolate and exponentially amplify a targeted region of DNA.

Because it can amplify from extremely small amounts of DNA, PCR is also often used to detect the presence of specific DNA sequences. DNA sequencing and genomics , one of the most fundamental technologies developed to study genetics, allows researchers to determine the sequence of nucleotides in DNA fragments. The technique of, developed in 1977 by a team led by, is still routinely used to sequence DNA fragments. Using this technology, researchers have been able to study the molecular sequences associated with many human diseases. As sequencing has become less expensive, researchers have of many organisms using a process called, which utilizes computational tools to stitch together sequences from many different fragments. These technologies were used to sequence the in the completed in 2003.

New technologies are dramatically lowering the cost of DNA sequencing, with many researchers hoping to bring the cost of resequencing a human genome down to a thousand dollars. (or high-throughput sequencing) came about due to the ever-increasing demand for low-cost sequencing. These sequencing technologies allow the production of potentially millions of sequences concurrently. The large amount of sequence data available has created the field of, research that uses computational tools to search for and analyze patterns in the full genomes of organisms.

Genomics can also be considered a subfield of, which uses computational approaches to analyze large sets of. A common problem to these fields of research is how to manage and share data that deals with human subject. Society and culture. Bruce Alberts; Dennis Bray; Karen Hopkin; Alexander Johnson; Julian Lewis; Martin Raff; Keith Roberts; Peter Walter (2013).

Garland Science. Griffiths, Anthony J.

F.; Miller, Jeffrey H.; Suzuki, David T.; Lewontin, Richard C.; Gelbart, eds. An Introduction to Genetic Analysis (7th ed.). Hartl D, Jones E (2005). Genetics: Analysis of Genes and Genomes (6th ed.).

Jones & Bartlett. King, Robert C; Mulligan, Pamela K; Stansfield, William D (2013). A Dictionary of Genetics (8th ed.). New York: Oxford University Press. Lodish H, Berk A, Zipursky LS, Matsudaira P, Baltimore D, Darnell J (2000). Molecular Cell Biology (4th ed.). New York: Scientific American Books.

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